Earliest AIDS, Part 4

Karl Fischer tyr-2 at bones.biochem.ualberta.ca
Sun Mar 1 20:46:02 EST 1998

In article <19980301225200.RAA24141 at ladder02.news.aol.com>,
trkeske at aol.com (TRKeske) wrote:

> Francois Simon and colleagues at the Centre Pasteur in France
> recently reported finding a strain of HIV that seemed halfway
> between the human and ape version of the virus (i.e., between
> HIV and SIV).  This was from the blood of a Cameroonian 
> woman who died in 1995 of AIDS [3].

The virus reported belonged to the HIV-1 group O (O=outlier).
Loussert-Ajaka I.  Chaix ML.  Korber B.  Letourneur F.  Gomas E.  Allen
E.  Ly TD. Brun-Vezinet F.  Simon F.  Saragosti
Variability of human immunodeficiency virus type 1 group O strains
isolated from Cameroonian patients living in
Journal of Virology.  69(9):5640-9, 1995

> This presents a slight problem.  If I understand correctly,
> a rapid and CONSTANT mutation means that you are
> statistically likely to move further away from SIV,
> never back closer to it

There are back mutations/reversions as well. One should keep in mind also
that not all mutations are viable.

> Dr. Ho and his team are suggesting that all 10 subtypes
> of HIV began with a single species jump, about 50
> years ago.  Dr. Simon's finding would not seem to fit in
> with this.

Yes it would - he found a strain of HIV-1 which genetically retains
homology with HIV-1 group M viruses while showing poor immunoreactivity
with antisera raised against group M viruses. Yet another branch on the
rootless phylogenetic tree.

> I would like to note that in general, an extremely high
> rate of mutation tends to be regarded as a measure
> of instability, and a sign of a YOUNG virus. 

Please give me the references (note plural!!) for this doozy of a statement.

<bull cookies snipped>
> [1] MSNBC Wire Report, Chicago, Feb. 3
> [2] Emerging Viruses: AIDS & Ebola, Leonard Horowitz
> [3] Reuters, "Sample Traces Earliest HIV case to 1959",
>      2/4/98

Sorry but 2/3 of your citations are wire releases - while the general/lay
public might be satisfied with these the majority of scientists reading
your "case" would remain skeptical (like myself) unless you cite the
journals in which these statements are supposedly published.

Looking for an vast improvement in your next installment.

Karl the hepB guy

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